The present invention concerns the field of mail processing and relates to a module for supplying mailpieces provided with a device for closing envelope flaps, particularly adapted for thick envelopes.
As shown very schematically in FIG. 6, envelope flaps are conventionally closed in a traditional mail processing machine by the pressure of gripping means at the entrance of a franking module 10 or any other module of this machine (most often an extraction module or possibly a weighing module) disposed immediately downstream of a supply module 10 in which these flaps were previously wetted by a moistening device 14 disposed at the outlet of this module on the path along which the mailpieces are conveyed.
Unfortunately, the simplicity of this envelope flap closure system is not without numerous shortcomings. In effect, the inventors observed in particular that, with this system, the envelope, although closed, is not closed correctly as the flap which was previously moistened is folded abnormally and damaged or even partially torn when the envelope emerges from the mail processing machine. FIGS. 3 to 5 of French Patent Application No. 98 14757 filed earlier by Applicants show examples of shortcomings encountered in day-to-day practice of a mail-sorting and -dispatching service.
Of course, such a deformation of the envelope is particularly critical, as the disturbance of its longitudinal jamming along the transport path creates defects at the level of printing of the postal indicia which is then no longer printed perfectly horizontally (a horizontal line will in that case be shown in the form of a wavy line).
Now, the consequences of such defects both in the closure of the envelopes and in the printing of the indicia are considerable (especially if these envelopes are full and in that case very thick), insofar as the damaged envelope or one whose postal indicia is deformed risks being rejected by the Postal Administration.
It is an object of the present invention to overcome these shortcomings in the closure of the envelopes by proposing a mailpiece supply module provided with a device, both simple and reliable, facilitating closure of the flaps of envelopes of considerable thickness. Another object of the invention is to propose a device which can also be employed with envelopes of smaller thickness (of nominal thickness) but of which the documents contained therein have been improperly inserted. Yet another object of the invention is to propose a device which allows a closure of the envelopes without employing complementary outside means. A further object of the invention is to propose a device which does not increase the initial space requirement of the supply modules and even one which reduces such space requirement.
To that end, the invention relates to a module for supplying filled envelopes in a mail processing machine comprising at least means for conveying these envelopes and a moistening device ensuring wetting of a flap of an envelope after said flap has been slightly moved apart from the body of the envelope, characterized in that it further comprises means for creating on said flap of the envelope a second line of fold above the natural crease line of the envelope existing at the level of the join of the body of the envelope with the flap.
The presence of these means for creating a second fold in the flap of the envelope makes it possible to close the latter without deformation and consequently to facilitate moistening and closure thereof by gripping cylinders arranged downstream.
According to a first embodiment, these means for creating a second line of fold comprise a pivoting blade of which a free end is intended to cooperate with a horizontal notch made in the body of the moistening device opposite this blade end, so as to xe2x80x9cbreakxe2x80x9d the flap of the envelope during its passage in the moistening device. The pivoting blade is advantageously mounted on this moistening device at the level of a separator intended to ensure, before wetting, the spacing of the flap with respect to the body of the envelope.
According to a second embodiment the means for creating a second line of fold comprises a pivoting separator of which a free end is extended in order to cooperate with a horizontal notch made in the body of the moistening device opposite this separator end, so as to xe2x80x9cbreakxe2x80x9d the flap of the envelope during its passage in the moistening device.
Furthermore, the supply module preferably comprises cylinders for gripping and extracting the mailpiece disposed just downstream of the moistening device and intended to ensure the closure of the envelope by pressure. The gripping/extraction cylinders are mechanically connected to said envelope conveying means via a movement transmission mechanism. This movement transmission mechanism preferably comprises means for transmitting the spacing of said conveying means to said gripping/extraction cylinders as a function of the thickness of the filled envelope and according to a predetermined ratio of reduction.
The gripping/extraction cylinders are advantageously either each associated with a roller having the same axis but of slightly larger diameter and intended firmly to mark the second crease line during passage of the envelope between the gripping/extraction cylinders, these rollers in that case preferably being made of a sliding material, or one of these gripping/extraction cylinders is associated with a first roller having the same axis and same diameter, a second pivotally mounted roller being intended to cooperate with this first roller in order firmly to mark the second crease line during passage of the envelope between the gripping/extraction cylinders.
The invention also relates to a mail processing machine comprising such a supply module. This may be a franking machine, or a folding and insertion machine.